A machine for making such infusion packages, with tags attached to the filter bags, is described in my U.S. Pat. No. 4,288,224. Reference may also be made to commonly owned Italian patent No. 721,347 and my copending U.S. patent application Ser. No. 227,767 now U.S. Pat. No. 4,382,355.
A dosimeter of the type described in the commonly owned Italian patent comprises an intermittently rotatable dosing drum with angularly equispaced metering chambers in the form of axially extending bores which, upon immersion of the drum in the comminuted mass, are filled up with particles of that mass. The bottom of the housing containing the drum has two holes above which each bore successively comes to rest. A metering plunger in line with the first hole enters an overlying bore from below and rises to a predetermined level within that bore to expel part of its contents into the mass overlying the drum at that point. When the partly emptied bore is stepped into alignment with the second hole, the expelled excess is swept off the upper drum surface whereupon a dispensing plunger enters the bore through that second hole and discharges its remaining contents into an outlet.
Such a dosimeter operates generally satisfactorily but has been found incapable of substantially exceeding a rate of about two dosings per second. Since a packaging machine for the filling and labeling of tea bags--as disclosed in my above-identified prior patent--can produce up to 500 bags per minute, the relatively slow mode of operation of an associated dosing apparatus represents a serious drawback.